Document blender2ogre material mapping

[paroj]

we use some heuristics when mapping materials from blender2ogre. e.g. here:

blender2ogre/io_ogre/ogre/material.py

Line 199 in a25db12

if mat.blend_method == "CLIP":

we should document them somewhere, so artists dont have to dig through the code.

[sercero]

There are lots of things missing in the material exporting.

For example we are not taking into account different BSDFs for example "Diffuse BSDF".

But to start documenting stuff is a good start.